From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 17F64A0559; Mon, 16 Mar 2020 19:28:04 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id EAF8A1C045; Mon, 16 Mar 2020 19:28:02 +0100 (CET) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by dpdk.org (Postfix) with ESMTP id 51DE11C036 for ; Mon, 16 Mar 2020 19:28:00 +0100 (CET) IronPort-SDR: RGSCvbkW6iLVMGxZKva8riKWR/gud1wT83Pv751Pl8F+4Bhl47eBg3mjxg8o/3Y0F+kC1DhIzQ rv7frhj567MA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2020 11:27:59 -0700 IronPort-SDR: lKLr24Uabc62RiHVLhV+ufQem+GjCKPZWsV/N8sjaeccDSHoM/z49I9/lS3kHLbjCtm+z17ioy QxWyvRKfIj5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,561,1574150400"; d="scan'208";a="267669957" Received: from vmedvedk-mobl.ger.corp.intel.com (HELO [10.251.87.131]) ([10.251.87.131]) by fmsmga004.fm.intel.com with ESMTP; 16 Mar 2020 11:27:49 -0700 To: =?UTF-8?Q?Morten_Br=c3=b8rup?= , dev@dpdk.org Cc: konstantin.ananyev@intel.com, yipeng1.wang@intel.com, sameh.gobriel@intel.com, bruce.richardson@intel.com, Suanming Mou , Olivier Matz , "Xueming(Steven) Li" , Andrew Rybchenko , Asaf Penso , Ori Kam References: <98CBD80474FA8B44BF855DF32C47DC35C60ED7@smartserver.smartshare.dk> From: "Medvedkin, Vladimir" Message-ID: <2baf9a76-a606-d376-dcce-b95c80fc6bb2@intel.com> Date: Mon, 16 Mar 2020 18:27:40 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35C60ED7@smartserver.smartshare.dk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Subject: Re: [dpdk-dev] [PATCH 0/3] add new Double Word Key hash table X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Morten, On 16/03/2020 14:39, Morten Brørup wrote: >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Vladimir Medvedkin >> Sent: Monday, March 16, 2020 2:38 PM >> >> Currently DPDK has a special implementation of a hash table for >> 4 byte keys which is called FBK hash. Unfortunately its main drawback >> is that it only supports 2 byte values. >> The new implementation called DWK (double word key) hash >> supports 8 byte values, which is enough to store a pointer. >> >> It would also be nice to get feedback on whether to leave the old FBK >> and new DWK implementations, or whether to deprecate the old one? > > > Who comes up with these names?!? > > FBK (Four Byte Key) and DWK (Double Word Key) is supposed to mean the same. Could you use 32 somewhere in the name instead, like in int32_t, instead of using a growing list of creative synonyms for the same thing? Pretty please, with a cherry on top! That's true, at first I named it as fbk2, but then it was decided to rename it "dwk", so that there was no confusion with the existing FBK library. Naming suggestions are welcome! > > And if the value size is fixed too, perhaps the name should also indicate the value size. > > > > It's a shame we don't have C++ class templates available in DPDK... > > In other news, Mellanox has sent an RFC for an "indexed memory pool" library [1] to conserve memory by using uintXX_t instead of pointers, so perhaps a variant of a 32 bit key hash library with 32 bit values (in addition to 16 bit values in FBK and 64 bit in DWK) would be nice combination with that library. > > [1]: http://mails.dpdk.org/archives/dev/2019-October/147513.html > > > Med venlig hilsen / kind regards > - Morten Brørup > -- Regards, Vladimir